The present invention relates in general to waveguides and in particular to a new and useful dielectric waveguide and method of making the same which has strong birefringent properties.
Two mutually orthogonally polarized waves can propagate in rotationally symmetrical dielectric waveguides. With a perfectly circular cross section of the waveguide, the two waves have exactly the same wave number. Consequently, no differences in propagation time occur between the two waves. In manufacturing such waveguides, however, as a rule, deviations from a perfect circular cross section must be taken into account, which are due to manufacturing tolerances, for example. The result is that the two mutually orthogonally polarized waves have unequal velocities of propagation. Because of the very small difference in the propagation velocities cross coupling occurs between the two waves. This leads to disturbances in the transmission of communications, for example.